饮冰三年-人工智能-Python-20 Python线程

进程：最小的数据单元

线程：最小的执行单元

一：

1：线程1

import threading #线程
import time
def Music():
    print("Listen Music Begin %s" %time.ctime())
    time.sleep(3)
    print("Listen Music End %s" %time.ctime())
def Game():
    print("Play Game Begin %s" %time.ctime())
    time.sleep(5)
    print("Play Game End %s" %time.ctime())
if __name__ == '__main__':
    t1 = threading.Thread(target=Music)
    t1.start()
    t2 = threading.Thread(target=Game)
    t2.start()

    print("ending......")

实例1

import threading #线程
import time
def Music():
    print("Listen Music Begin %s" %time.ctime())
    time.sleep(3)
    print("Listen Music End %s" %time.ctime())
def Game():
    print("Play Game Begin %s" %time.ctime())
    time.sleep(5)
    print("Play Game End %s" %time.ctime())
if __name__ == '__main__':
    t1 = threading.Thread(target=Music)
    t1.start()
    t2 = threading.Thread(target=Game)
    t2.start()
    t1.join()
    t2.join()
    print("ending......")

线程join

import threading #线程
import time
def Music(musicName):
    print("Listen Music【%s】 Begin %s" %(musicName,time.ctime()))
    time.sleep(3)
    print("Listen Music【%s】 End %s" %(musicName,time.ctime()))
def Game(playName):
    print("Play Game【%s】 Begin %s" %(playName,time.ctime()))
    time.sleep(5)
    print("Play Game【%s】 End %s" %(playName,time.ctime()))
if __name__ == '__main__':
    t1 = threading.Thread(target=Music,args=("My Heart Will Go On",))
    t2 = threading.Thread(target=Game,args=("植物大战僵尸",))
    threads=[]
    threads.append(t1)
    threads.append(t2)
    for t in threads:
        t.start();
    print("ending......")

线程参数

import threading #线程
import time
def Music(musicName):
    print("Listen Music【%s】 Begin %s" %(musicName,time.ctime()))
    time.sleep(3)
    print("Listen Music【%s】 End %s" %(musicName,time.ctime()))
def Game(playName):
    print("Play Game【%s】 Begin %s" %(playName,time.ctime()))
    time.sleep(5)
    print("Play Game【%s】 End %s" %(playName,time.ctime()))
t1 = threading.Thread(target=Music,args=("My Heart Will Go On",))
t2 = threading.Thread(target=Game,args=("植物大战僵尸",))
threads=[]
threads.append(t1)
threads.append(t2)
if __name__ == '__main__':
    t2.setDaemon(True)
    for t in threads:
        t.start();
    print("ending......")

守护线程

# 多线程为什么要使用锁？
# 多线程共用一个数据集，不使用可能会造成数据不准确
#1：引入多线程模块
import threading
import time
# 2：定义一个变量（数据集）
num=100
# 3:定义一个方法，操作全局变量
def sub():
    global num
    temp = num
    time.sleep(0.001)
    num=temp-1
# 4：创建多个线程
ts=[]
for i in range(0,100):
    t=threading.Thread(target=sub)
    t.start()
    ts.append(t)
for t in  ts:
    t.join()
print(num)

未加锁，数据结果有误

# 多线程为什么要使用锁？
# 多线程共用一个数据集，不使用可能会造成数据不准确
#1：引入多线程模块
import threading
import time
# 2：定义一个变量（数据集）
num=100
# 3:定义一个方法，操作全局变量
# 5:创建锁
lock=threading.Lock()
def sub():
    global num
    # 5.1 加锁
    lock.acquire()
    temp = num
    time.sleep(0.001)
    num=temp-1
    # 5.2 释放锁
    lock.release()
# 4：创建多个线程
ts=[]
for i in range(0,100):
    t=threading.Thread(target=sub)
    t.start()
    ts.append(t)
for t in  ts:
    t.join()

print(num)

同步锁

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饮冰三年-人工智能-Python-20 Python线程

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